Drop type piano action



June 26, 1962 H. G. BEHNING DROP TYPE PIANO ACTION 2 Sheets-Sheet 1Filed Sept. 16, 1960 @en ALM-J ,d+ um f//k Eh en OO MMO @w .u Om w/ OOJune 26, 1962 H. G. BEHNING DROP TYPE PIAN@ ACTION 2 Sheets-Sheet 2Filed Sept. 16, 1960 NYENDTOK/ New vj C3. ehvkgyg ALM/(MJ, pm

QAw-reruoxsY/ United States Patent O Illinois Filed Sept. 16, 1960, Ser.No. 56,403 10 Claims. (Cl. 84-240) This invention relates toa pianolaction of the drop type in which part of the .action is disposed belowthe level of the keys and the actuating motion is transmitted through anupright pull link pivotally joined at opposite ends to the rear end ofthe key lever and the free end of the whip. The invention is `directedmore particularly to the pivotal `and detachable coupling of the pulllink land the key lever through the medium of a `grommet composed ofresiliently yieldable material such as rm rubber.

The general object is to correlate the construction of the grommet withthe rear end of the key in a novel manner such as to substantiallyred-uce the time required to couple the key levers to the pull links andalso facilitate disassembly and reassembly during releveling of the keysin the initial manufacture of the piano or after service use.

'Ilhe invention also resides in the-novel construction of the grommetand the manner of its coaction with the pull link to perform theforegoing new functions.

Other objects and advantages. of the invention will become apparent fromthe following. detailed description taken in connection with theyaccompanying drawings, in which FIGURE l is `a fragmentary verticalsectional view of a piano action embodying'the novel features of lthepresent invention.

FIG.l 2 is a perspective view of the notched rear end of the piano key.Y

FIGS. 3 and 4 are `fragmentary sections taken respectively along thelines 3 3 yand 4-4 of FIG. l.

FIG. 5 is a longitudinal section of the rubber grommet.

(FIGS. 6 and 7 are fragmentary sections of ya 4part of FIG. lillustrating successive steps in coupling the key to the pull link ofthe action.

FIG. 8 is a fragmentary section taken along the line 8--S of FIG. 7.

FIG. 9 is Ia fragmentary View similar to FIG. 6 illustrating the mannerof uncoupling the .key yand the pull link. l

In `a piano action shown in the drawingsl for purposes of illustration,the pull link indicated generally lat 10 is arranged to transmit theactuating cr upward movement of the rear end of a key 11 to .a whiplever 12 liur throwing a hammer 13 against `a piano string 14. The keyis,

-apertured -at 15 vintermediate its ends to telescope down over a pin 16upstanding from a pad 17 on which the key is fulcrumed in the usual wayon .a balance rail 18 with the rear end of the key normally resting onya pad 19 extending along the rear edge of the key bed 20.

The link 10 includes a lower part 21 made of wood and pivotally joinedto the forked end of the whip 12. The upper part of the link is Va metalscrew 22 having a slotted head 23 and an elongated shank 24 threaded atits lower end and screwed into `a hole in the upper end of the woodenpart 21 in Iaxial alinement with the latter.

The key motion is transmitted to theflink through a fork 25 securedtothe key and having laterally spaced legs 26 prjecting from the rearend of the key and straddling the shank of a screw immediately below thehead 23. Herein, the fork is a metal plate 32 fastened on top of the keyby Ia screw 27 and a lug `28 embedded in the wood of the key. Beyond thekey end, the plate is 3,040,614 Patented June 26, 1962 ice notched asindicated-at 29 to form the legs 26 whose opposed edges 30 at theirouter ends are substantially parallel .and define between them .arelatively narrow slot. At their inner ends, the edges 30 are arcuate inshape and define a generally Icircular hole 31 somewhat larger than thewidth of the slot 30.

yIn yaccordance with the present invention, the fork 25 is lpivotallyand detacri'ably coupled to the screw 22 of the pull link through themedium of a sleeve-like grommet 33 of resiliently yieldable materialtelescoped on the screw shank inv abutment with the head 23 and of aspecial construction `correlated with the notch of the fork 25 so as toenable coupling land uncoupling of the two to be achieved bymanipulation of thekey lever 11 as an incident to mounting the latter onor removing the same from the fulcrum pin 16.

Preferably, thegrommet is molded .and composed of "relatively .firmrubber, preferably about 50 asmeasured by a Shore Durometer, andcomprises a sleeve 34 several times las long as the thickness oi' thefork 25 and having ia central hole 35 of-about the same diameter as theshank 24 of lthe screw so that the grommet may beslid easily along theshank to bring an end ange 36 on the grommet into abutment with theunderside `of the screw head 23. The flange is somewhat larger than thescrew head .and restsatly against the Vtop'surface of the fork 25 whichis bentupwardly so as to be disposed perpendicular to the pull link 10in the idle position of the latter when the key lever-is released.

The wall thickness` of the sleeve is about /s of an inch over the upperhalt .-portion whose outer suriace 37 is generally cylindrical having adiameter slightly less, by [about 0.005 of aninch, than the hole 31 inthe fork 25. Thus, when the grommet is disposed in the hole with theflange 36 .abutting the underside/of the screw head, the rubberV of thegrommet wall is compressed slightly thus creating additional resistanceto sliding of the grommet along the shank and away from the screw headunder the inertia of the action parts when the motion thereof isarrested as the hammer 13 comes against the stri-ng 14. In the presentinstance, the resistance to the sliding of the grommet away from thescrew head is increased by an enlargement formed on the shank of thescrew and spaced axially away from. the head 23 a distance preferablyonly .slightly greater than the thickness of the forkV -be apparent thatthe ribs produce a further increase in the external diameter below thefork 25 as shown in FIGS. 3 and 4, thus forming in eiiect a groove 39`in which the deiiningV edges of the fork hole are seated thus furtherincreasing the resistance to displacement of the fork along the shank soas to maintain the grommet in abutment with the screw head under theforces which accompany the normalV operation of the piano action. Owinghowever to the radial yieldability of the grommet wall 34, the fork 215may be shifted axially away from ythev liange 36 or transversely of the'shank axis during coupling or uncoupling of the two. This is permittedby compression of the rubber of the sleeve wall thus allowing the sleeveto pass through the narrower slot 30.

The lower or free end portion of the grommet is preferably shaped tofacilitate and actually pilot the insertion of the grommet into theyhole 31' of the fork. For this purpose, the ydiameter of the lower halfportion is decreased progressively being substantially at thelongitudinal center of the sleeve so as to taper the surface 40 i downto a diameter of about 1%4 of an inch at the lower end of the sleeve. Itwill be observed that this diameter is substantially less than that ofthe fork hole 31 so that the small end of the grommet may easily beguided into the hole.

With the grommet 33 constructed as above described in relation to thenotch of the fork 25 on the key and the size and shape of the screwshank, the coupling of the fork to the pull link and uncouplingtherefrom is effected in the following manner. After the action properhas been mounted in a piano case, the keys 11 are mounted on the bed 20by resting the keys one by one on the pad 19 as shown in FIG. 6 andswinging the pull link to pass the screw shank through the slot 30 ofthe fork. Next, the key is swung downwardly to enter the pin 16 throughthe key hole and settle the key on its fulcrum 17 at the same timeguiding the tapered lower end of the sleeve 34 into the hole 31 as shownin FIG. 8 and in full in FIG. 7. The assembly is then completed bystriking a sharp blow on the free end of the key to raise the key to theposition shown in phantom in FIG. 7. During this motion and due to theinertia of the action parts, the fork is slid upwardly along the sleevethus compressing the rubber as it passes the enlargement 38 and comesinto abutment with the flange 36 of the grommet. The edges of the forkthus become disposed in the vgroove 39 and the fork is thus heldeffectually against axial displacement relative to the screw shank.

With the key and pull link thus coupled together, it will be apparentthat the flange 36 constitutes a yieldable cushion between the fork andthe screw head for trans- 1 mitting the key motion to the whip 12 whileallowing for relative pivotal movement of the key and link by yieldingof the rubber of the grommet. The coupling is maintained effectually inall positions of the parts in normal service use because of thecompression of the grommet wall within the hole 31 of the fork combinedwith the enlargement of the sleeve 34 below the fork by the rib 38. Thepivotal movement between the link and the key which accompanies thenormal striking and release of the key is accommodated by yielding ofthat part of the rubber which joins the screw shank and the fork.

At the same time, the improved grommet connection described permitsconvenient uncoupling and separation of the key from its pull link andrecoupling of thektwo by simple manipulations of the key in lifting thekey off from and replacement of the same on the fulcrum guide ing. Theportion of the plate 32. adjacent the hole 31 first comes against theforward edge of the gromrnet flange 36, as shown in FIG. 9, after whichthe flange acts as a fulcrum as the raising of the key is continued toswing the notch 29 downward and7 by compressing the sleeve 34, cause thelatter to pass outwardly through the slot 30 thus freeing the key forkfrom the grommet. To recouple the key and pull link, the manipulation ofthe key and pull link as above described is repeated.

It will be apparent from the foregoing that by the novel construction ofthe coupling grommet and the manner of its correlation with the notch ofthe key fork 25 a new and simplified mode of assembling piano actions isachieved. That is to say, a partial and easy prel'uninary assembly (FIG.7) is started a's an incident to placing the key on its fulcrum. Then,the final assembly is effected simply by striking a downward blow on thefree end of each key, the vsame as in normal service use of the piano.Removal and replacement of the keys to level the initial manufacture orservice use is similarly facilitated. As a consequence, the overall costof initial manufacture of a piano of the drop action type as well as thelater servicing thereof is reduced substantially as compared with thatof prior constructions.-

This application discloses subject matter common Yto and genericallyclaimed in copending applications of Phil lip I. Roehrig, Serial No.787,230, filed January 16, 1959, and Harold R. Anderson, Serial No.808,477, filed April 23, 1959, no claim being made herein to such commonsubject matter.

I claim as my invention:

l. In a piano action or" the drop type, the combination of, a manuallyoperable key lever fulcrumed intermediate its ends, a fork rigid withand projecting from the rear end of said key and having a rearwardlyopening notch comprising a generally, circular hole at the closed end ofthe notch communicating with a narrower parallel sided slot at the openend of the notch, an elongated endwise reciprocable link including ametal shank having a head thereon, a sleeve of resiliently yieldablematerial several times as long as the thickness of said fork snuglytelescoped on said shank and projecting through said hole and compressedby the defining edges thereof, and a flange formed on the upper end ofsaid sleeve and abutting against the underside of said head and the topof said fork, said sleeve being dimensioned for insertion endwise downthrough said hole and also for movement laterally out of the notchthrough said slot.

2. The combination as defined by claim l in which the width of said slotis large enough to permit shifting of the sleeve laterally out of saidnotch by compression of the material of the sleeve wall as it passes outthrough the slot.

3. The combination as defined by claim l including an enlargement onsaid shank disposed below said notch and within said sleeve and actingto increase the outside diameter of the sleeve and form y'with saidflange a shallow groove in which the legs of said fork are seated andrestrained against axial displacement relative to the sleeve.

4. The combination as defined by claim l in which the sleeve below saidfork is reduced to an outside diameter smaller than said hole.

5. The combination as defined by claim 4 in which the lower end portionof said sleeve below said fork is tapered down to a diameter smallerthan said fork hole.

6. In a piano action of the drop type, the combination of, a manuallyoperable key lever fulcrurned intermediate yits ends, an elongatedendwise reciprocable link having a head thereon, a sleeve of resilientlyyieldable material snugly telescoped on said link and having a flange atthe upper end larger than the vrest of the sleeve and abuting againstthe underside of said head, and a fork rigid with and projecting fromthe rear end of said key and having a rearwardly opening notch with thelegs thereof straddling said sleeve and abutting the underswinging ofsaid key lever about a fulcrum defined by theV edge of` said flange.

7. In a piano action of the drop type, the combination of, a manuallyoperable key lever fulcrurned intermediate its ends, a fork rigid withand projecting from the rear end of said key and having a rearwardlyopening notch, an elongated endwise reciprocable link having a headthereon, a sleeve of resiliently yieldable material several times aslong as the thickness of said fork snugly telescoped on said link andprojecting through said notch and compressed by the defining edgesthereof, and a flange formed on the ,upper end of said sleeve andabutting against the underside of said head and the top of said fork,said sleeve being dimensioned for insertion endwise down through theclosed end of said notch and also for movement laterally out of thenotch by radial compression of the sleeve. f

8. In a piano action of the drop type, the combination of, a manuallyoperable key lever fulcrurned intermediate 1ts ends, a yfork rigid withand projecting from the rear end of said key and having a rearwardlyopening notch defined by a `generally circular hole at its inner closedi projecting through said notch hole' and held therein by they notchedges but compressible edgewise for movement out of the notch betweensaid laterally spaced edges, and a flange formed on the upper end ofsaid sleeve and abutting against the top of said fork,'said sleeve belowi said fork tapering to a diameter-small enough to 'permit of endwiseinsertion of the sleeve into said hole.

9. In a piano action ofthe drop type, the combination t of, a manuallyoperable key lever fulcrumed intermediate its ends, a fork rigid withand projecting from the rear end of said key and having a rearwardlyopening notch den'ed by a generally circular lhole'at its inner closedend and laterally spaced edges located at the outer end .of the notchandv spaced closerk together than the diameter of said hole, an uprightelongated endwise reciprocable link, a sleeve of resiliently yieldablematerial severaltimes as long as the thickness of said fork telescopedon said link, means onrsaid link holding said sleeve against endwisedisplacementalong the link, including a rib `formed on and extendingaround said link within said sleeve and having a diameter larger than fthe internal Wall of the sleeve whereby to expand and grip said wall asan incident to insertion of the link through the sleeve, said sleeveprojecting through said notch hole and held therein by the notch edgesbut compressible edgewise for movement out of the notch between saidlaterally spaced edges, and a flange formed on the up- Vper end of saidsleeve and abutting against the top of said `mediate its ends, a forkrigid with and projecting from the rear end of said key and having aVrearwardly opening notch defined by a generally circular hole at itsinner closed end and parallel edges located at the outer end ofthe'notch and spaced closer together than the diameter of said hole, anupright elongated` endwise reciprocable link, a sleeve of resilientlyyieldable material several times as long as the thickness of said forktelescoped on said link, means on said link holding said sleeve againstendwise displacement along the link, said sleeve projecting through saidnotch hole, and a ange formed on the upper end of said sleeve, saidsleeve below said fork tapering to a diameter smaller than said hole topermit of endwise insertion of the sleeve into said y References Citedin the le of this patent UNITED STATES PATENTS Mason Dec. 3l, 19402,324,037 Socin July 13, 1943 2,548,890 Knoblaugh Apr. 17, 1951

